This invention relates to two-phase fingers to passively reorient objects while picking them up and thereafter grasping them securely.
Robotic research has long been interested in the ability to grasp and manipulate a large and varied set of objects. Due to stringent requirements on speed, precision, and reliability, the automation industry however has preferred simple gripping solutions that can accurately localize and securely grasp a small set of objects [1]. Furtherance, the need for object manipulation at assembly is often bypassed by specialized part feeders which present the parts in a pose suitable for picking and use.
Robotics research has been driven, and is still driven in part today, by the needs of factory automation. The last two decades have seen a remarkable evolution of robotic manipulators leading to a precision of 30 microns, speeds of a few meters per second, the availability of force feedback and force control, as well as safety and compliance. Unfortunately, the lack of robust solutions for object manipulation has limited the role of these remarkable machines to mostly pick-and-place.
Getting an object in a fitting pose for an assembly, either by picking it up in the required pose or by regrasping it, is crucial for the success of the assembly. Often, the approach practiced in industry is to avoid the need for regrasping. An ancillary system deals with part feeding by singulating and locating a parts from a pile by passing them through specially designed pathways that reorient them and present them to the robot in an already suitable pose. This approach, although proven robust, impinges on important space, time, and set-up requirements, leading to huge costs in the set-up of a new assembly line. When the product changes, little of the set-up can be reused. These factors discourage the possibility of assembly automation for products with short upgrade cycle time.
The large market for automation of electronic product assembly and the demand from small scale industries for affordable automation are two major contributors to the rising interest in flexible automation. It aims for automation systems that are modular, easy to set up and adapt, and easy to integrate among human co-workers [23, 24]. Dexterity has been identified as one of the major roadblocks and essential capabilities needed to address the challenges in next-generation automation [25]. Rather than general-purpose dexterity, we explore a solution to perform a particular reorientation precisely and reliably, and with the ability to be easily adaptable to other parts and systems with minimal reconfiguration.
It is therefore an object of the invention to provide a two-phase gripper that allows reorientation of an object followed by secure grasping.